Summary

On 24 January 2011, at about 1800 Eastern Standard Time, a De
Havilland Aircraft DH-82A (Tiger Moth) aircraft, registered VH-WHW
(WHW), departed Toowoomba, Queensland on a private local
flight.

On board was the pilot in command (PIC) and a flying instructor
from the local Aero Club. The PIC conducted a pre-flight
inspection, which included a check of the fuel, oil and control
cables. He determined that WHW was serviceable and had sufficient
fuel for the flight. There were no loose items in the aircraft's
storage locker or in the cockpit.

About 15 minutes after takeoff, the flying instructor, who was
acting as the handling pilot at the time, initiated a left turn to
return to the airport. The PIC recalled that, during the turn, WHW
suddenly pitched down followed by a second, even more severe, pitch
down motion. Both the PIC and the handling pilot recalled that the
control stick did not move when WHW pitched down.

In response to the sudden and uncommanded nose down motion, both
pilots attempted to raise the nose by applying back pressure on the
control stick. Their actions had no effect and WHW continued to
pitch nose down until the aircraft became inverted.

The aircraft was about 100 ft above the trees and inverted when
it began to climb. Both pilots felt significant g-force followed by
the collision with the trees.

The aircraft came to rest upside down on the side of Mount
Davidson in bushland. Both occupants sustained serious
injuries.